Density of magnesium and magnesium-lithium alloys in solid and liquid states

New experimental data are presented on the density and thermal expansion of solid and liquid magnesium and ultralight magnesium-lithium alloys containing 23.03 and 30.02 at.% Li, respectively. The measurements were performed using the dilatometer method and the gamma-ray attenuation technique in the temperature range from 145 to 1244 K for magnesium and from 293 to similar to 1000 K for the alloys. The density changes during the solid-liquid phase transition were directly measured for Mg and the Mg70Li30 alloy. The temperature dependences and reference tables of the investigated volumetric properties were developed. A comparison of the obtained results with literature data was made. The study showed that the eutectic composition in the magnesium-lithium system differs from 23 at.% Li. The concentration dependence of molar volume of the magnesium-lithium liquid system was found to be almost linear in the interval of 0-30 at.% Li and deviated noticeably from the corresponding dependence for an ideal mixture.